<p>I just want to chime in with how static variables can be bad for multi threaded code, yet they aren't considered as bad as global variables. E.g. the find_path guido example will explode if called by 2 threads in tandem. I believe this is more apparent and frowned upon when caused by global variables.</p>

<p>Hasn't python given enough temptations to avoid multithreading already?</p>
<p>Allowing these fast, local, persistent static variables is like allowing braces instead of whitespace - the good coders will manage either way but the bad will do bad things with it.</p>
<p>--Yuval</p>